I believe PF contributions should be made from the time the company becomes eligible for the act. However, seniors may provide better guidance.
Another point to note is that there is no need to worry. Each of you will have a PF Account Number. All PF contributions and the interest earned are tax-free. This serves as a retirement solution and a fixed deposit for later in life. You can always track the amount deposited in your PF Account.
I have shared a link to the PF Act articles and highlighted the key points below:
1. PF Act applies to any organization with more than 20 employees.
2. Once covered under the PF Act, the company remains covered even if the employment drops below 20 later.
3. Employer cannot reduce wages to contribute to your PF without affecting your gross pay. Only a 12% deduction is allowed for your contribution. The company's contribution can be adjusted from other components without reducing your gross pay. If your gratuity, bonus, etc., are part of your CTC, such deductions do not violate statutory compliance.
[EPF Act 1952, EPF Act in India, EPF Rules and Regulations, EPF Rules for Withdrawal](http://www.epf.net.in/epf-act-and-rules.htm)
[EPF India](http://epfindia.com) <link fixed>